1. Field of the Invention
The present invention relates generally to equipment for cutting holes in surfaces, such as walls or ceilings, for receiving construction components, such as electrical outlet boxes, recessed light fixtures, and the like. More specifically, the present invention concerns a hole cutting tool that provides a frame assembly which is self-adhering to the surface and carries a removable template for use in cutting an accurately located and precisely shaped hole. The unique frame assembly provides multiple selectable, pneumatically isolated suction chambers that enable the self-adhesion function even when the frame assembly is placed over existing holes in the surface. The versatile self-adhesion function enables the inventive frame assembly to be used to cut a wide variety of desirably shaped holes using one or more templates in a handsfree manner. In a preferred embodiment, the suction chambers are formed in part by a unique gasket that enables the frame assembly to self-adhere to porous surfaces. In the preferred embodiment, the removable templates enable dust particles created during the cutting process to be simultaneously vacuumed away regardless of the orientation of the template relative to the frame assembly.
2. Discussion of Prior Art
In the construction industry, it is often necessary to cut a particularly configured hole in an existing wall or ceiling of a finished commercial or residential building. For example, an electrical contractor may need to cut a hole in a finished wall to receive an electrical outlet box when installing a new outlet or switch, or may need to cut a hole in a finished ceiling to install a new fixture, such as a recessed light. It is desirable in the construction industry to accurately position these holes, shape them to closely correspond to the outline of the box involved, and cut them in an efficient and clean manner. However, prior art hole cutting techniques (with the exception of the prior art technique previously developed by one of the inventors of the present invention as disclosed and incorporated below) were defective in meeting the needs of the industry. These problems have previously been identified in U.S. Pat. No. 5,613,811, having a common inventor with the present invention and licensed exclusively to the assignee of the present invention, issued Mar. 25, 1997, and entitled DUST-FREE METHOD AND APPARATUS FOR LOCATING AND CUTTING HOLES FOR ELECTRICAL OUTLET BOXES, RECESSED LIGHT FIXTURES AND THE LIKE (“the Tillemans '811 patent”), which is hereby incorporated by reference herein.
The hole cutting apparatus disclosed in the Tillemans '811 patent was a significant advance in the field and solved many of the problems identified in the art at the time. However, it has been determined that electricians in the field are increasingly needing to place electrical outlet boxes that are larger than the standard double gang outlet box, such as two or more double gang boxes in series in the same hole location. Although an electrician could simply use a double gang box template to cut overlapping cuts to form a larger hole, such an application was problematic with the Tillemans '811 apparatus because the previously cut hole would undesirably interfere with the self-adhesion properties of the Tillemans '811 apparatus. That is to say, when a portion of the single vacuum chamber of the Tillemans '811 apparatus overlain an existing portion of the hole, the vacuum pressure was compromised to the point the apparatus would no longer adhere to the wall. In addition, the Tillemans '811 apparatus was ineffective at adhering to a porous surface, such as a “popcorn” ceiling.